JPH0367411B2 - - Google Patents

Description

Claim 1: An elongated linear transducer capable of converting high-frequency electrical energy into high-frequency mechanical vibration; an elongated coupling body having one end immovably fixed to one end of the elongated transducer; and an elongated coupling body that is detachable from the other end of the coupling body. a vibrating body having an elongated linear surgical tip that can be mounted, the vibrating body having a total length approximately equal to the wavelength λ of a longitudinal vibration wave when the vibrating body vibrates at a resonant frequency F; The vibration wave has an antinode surface near the joint end of the transducer and the combination body, and a nodal surface near the other end of the combination body, and is an ultrasonic wave for cutting and removing tissue from a recessed surgical site. In a sonic surgical handpiece, the coupling body is aligned with the longitudinal axis X of the transducer.
a generally straight first portion having a longitudinal axis coincident with said longitudinal axis Most of the entire length of the bonded body is formed in a circular cross section, and a portion of the surface of the bonded body is cut off near the nodal surface, so that the mass of the bonded body is An ultrasonic surgical handpiece characterized in that the mass is reduced compared to the mass of a linear combination of length equal to the length of the combination along axis X and longitudinal axis X'.

2. The ultrasonic surgical handpiece according to claim 1, wherein a portion of both diametrically opposite side surfaces of the combined body are removed by planing into substantially parallel planes.

3. The ultrasonic surgical handpiece of claim 2, wherein the planing plane is located in a plane parallel to a plane containing the longitudinal axes X and X'.

4 The above-mentioned bonded body is obtained by the following formula by the above ^- mentioned removal. 4. Ultrasonic surgical handpiece according to claim 3, characterized in that the handpiece is reduced by a mass M determined by the ultrasonic surgical handpiece.

5. The transducer is characterized in that it has a nodal surface disposed at an intermediate position between both ends thereof, and has support means disposed on the nodal surface of the transducer for supporting the transducer. An ultrasonic surgical handpiece according to claim 1.

6. An ultrasonic surgical handpiece according to claim 5, wherein said support means includes means for flowing a cooling fluid through said support means.

7. The ultrasonic surgical handpiece of claim 6, wherein the transducer support means includes a plurality of radially inwardly directed projections on a support surrounding the transducer.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to ultrasonic surgical instruments useful for removing flaky tissue from generated tissue. More particularly, the present invention relates to an ultrasonic surgical handpiece having a transducer and a bendable combination and a method of manufacturing the same.

Description of the Prior Art Ultrasonic surgical instruments, generally associated with handpieces, were first used in eye surgery, particularly cataract ablation, but are now widely used in a variety of surgical procedures. This known ultrasonic handpiece generally uses piezoelectric or magnetostrictive transducers that convert high frequency electrical energy into mechanical shocks or vibrations. The transducer essentially consists of a transducer fixed at one end, such as by brazing or welding, to an elongated body. The combination in turn supports an elongated surgical probe or tip at its other end.

The electromechanical transducer body with the transducer, the coupling part and the probe protects the frame from mechanical vibrations and interconnects the coolant part, the transducer body and the electrical energy part for driving the transducer. It is supported by the frame via coupling means for coupling in conjunction with the frame. This known ultrasonic handpiece is known, for example, from US Pat.
Disclosed in No. 3805787.

In general, known ultrasonic handpieces having an elongated surgical probe coaxial with the frame have a 3/4λ length transducer, i.e. the length of the transducer and combination is 3/4 of a wavelength. and a surgical probe with a length of 1/4λ assembled to obtain a sufficient wavelength at the tip coupling surface on or near the nodal surface. Since this handpiece has a linear shape, it is limited to certain surgical methods. For example, when the affected area to be operated on is located deep inside the living body, it is not always possible to have a good view because the handpiece frame and the surgeon's hand holding the frame block the line of sight toward the surgical tip. I can't get it. Additionally, such prior art linear ultrasonic handpieces are particularly limited in use in microsurgery because the handpiece and the surgeon's hand interfere with the surgical microscope.

One attempt to provide an ultrasonic surgical handpiece that overcomes the difficulties of linear handpieces described above is disclosed in U.S. Pat. No. 4,526,571. In this prior art device, a typical linear transducer body is assembled to a typical wave node with respect to the surgical tip via a coupling body, and a 1/2λ
The curved extension coupling of the surgical probe and the surgical tip are such that the longitudinal axis of the surgical tip is at an angle of, for example, 15° with the longitudinal axis of the transducer body.
forming an extension of virtually 3/4λ, forming an angle of
It is inserted between the transducer body and the common attachment point where it mates. This transducer body has successfully solved the problem of visibility at the surgical site when performing surgery deep inside the organism and in close and restrictive body orifices; The length of the additional portion reduces the ability of the device to be used with a surgical microscope under certain conditions. Furthermore, some surgeons accustomed to operating short, straight handpieces find it difficult to switch to a longer handpiece due to differences in maneuverability and balance. Thus, there remains a need for an improved surgical handpiece designed with improved visibility into the surgical tip and minimal interference with the surgical microscope.

It is also known that longitudinal ultrasonic vibrations are transmitted through an elongated section consisting of either a straight section and a curved or bent section. For example, U.S. Pat. No. 3,546,498 discloses a transmission line consisting of a series of straight ring nodes connected by short radius bends located at critical locations, i.e., at the node or antrum of the transmission element. Disclosed.

A first object of the present invention is to improve the above-mentioned disadvantages of the prior art handpieces, to be shorter than the known curved handpieces, to replace the straight handpieces and to use a control device of the same frequency. A bendable ultrasonic surgical handpiece that is easy to use and operate is provided.

Another purpose is to create a curved joint by positioning the surgical tip between the nodal surface and the antinodal surface near both ends of the engaging body, in which the longitudinal axis of the surgical tip is arranged at an angle with the longitudinal axis of the transducer. An object of the present invention is to provide a handpiece for ultrasonic surgery using.

Another object is to provide an ultrasonic surgical handpiece that has improved balance to fit in the surgeon's hand, thereby making it easier to manipulate and less tiring to use.

Another object is to provide an ultrasonic surgical handpiece for use with a surgical microscope that does not substantially interfere with the use of the microscope, at least when using a 300 mm focal length objective.

Another object is to provide an ultrasonic surgical handpiece in which both the surgical tip and drive train components of both the straight and flexure handpieces are interchangeable.

Furthermore, another objective was to be easy to operate and fit in the surgeon's hand, be short enough to avoid fatigue, and be 1/4 λ
An object of the present invention is to provide a method for manufacturing a bendable ultrasonic surgical handpiece using a surgical tip of the present invention.

SUMMARY OF THE INVENTION In order to obtain the inventive step, non-conventional objects and advantages of the present invention, the important features of the present invention are such that it can be easily used by operating room personnel in place of known linear handpieces. An object of the present invention is to provide an improved bendable ultrasonic surgical handpiece. This handpiece plugs into a commercially compatible controller on the same frequency and works with existing surgical tips used in commercially compatible linear handpieces. is designed to. This means that the coupling member is bent at an angle to the longitudinal axis of the transducer at the midpoint between the two ends of the coupling body, i.e. between the nodal surface and the antinodal surface located at both ends of the coupling body. This can also be achieved by using compatible linear transducers and vibratory impedance matching to replaceable chips at the desired operating frequency. Also, to achieve this, the bent and straight combinations have the same axial length;
In addition, a portion of the bent type joint is removed on or near the nodal surface, that is, near the joining point of the surgical tip. Preferably, this portion of the material is removed by planing a flat section lying in a plane parallel to a plane containing the respective longitudinal axes of the straight and bent sections of the combination.

[Brief explanation of drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The inventive step, non-conventional features and advantages of the invention will be apparent from the following accompanying drawings and detailed description in conjunction with the drawings.

FIG. 1 is a longitudinal cross-sectional view of a prior art linear ultrasonic surgical handpiece, which the present invention seeks to improve.

FIG. 2 is a plan view of the transducer body and surgical tip portion of the ultrasonic surgical handpiece using the present invention.

3 is a side view of the instrument shown in FIG. 2; FIG.

4 is an enlarged side view of the combined portion of the instrument shown in FIG. 3; FIG.

5 is a sectional view taken along arrow 5-5 in FIG. 4. FIG.

FIG. 6 is a composite view showing the vertical axes of the straight and bent handpieces.

FIG. 7A is a partial side view in partial cross section of the bendable handpiece of the present invention showing the support method disposed on the nodal surface.

FIG. 7B is a cross-sectional view of the embodiment shown in FIG. 7A along the nodal plane Z-Z.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring in detail to the drawings, FIG. 1 shows a conventional ultrasonic aspirator as disclosed, for example, in U.S. Pat. No. 3,693,613. Although this suction device is still widely used in surgical procedures, the present invention improves on this. This ultrasonic surgical handpiece is designated by the reference numeral 10,
It has a frame section 12 generally designated by reference numeral 14 which surrounds and supports a vibration inducer. The vibration inducer 14 is an amplifying section or coupling section or an amplifier section or coupling section 1 having a magnetostrictive transducer element 16 and a removable surgical tip 20 mounted at its distal end.
Formed from 8. Radio frequency energy for driving the transducer is supplied via a conductor 22 connected to a coil 24 wound around the transducer 16 located within the frame 12 . Coolant is circulated through the framework by inlet conduits 26 and outlet conduits 28, respectively.

Said vibrating body body 14 is in turn assembled to the end of the frame part 12 and is positioned and assembled in the cavity 30 of the support element 32 protruding therein. A pair of elastic gasket portions 36, one on each side of the radially expanding flange 34, efficiently protects the support element 32 and the frame portion 12 from vibrations induced from the vibrator body 14. It protects and supports the vibrating body 14.

The liquid structure 38 for cleaning and suctioning is assembled to the end of the support element 32 by screw coupling means 40 or the like, and securely holds the elastic gasket part 36. The liquid inlet 42 communicates with a cylindrical liquid chamber 44 intermediate the hollow cylinder 46 of the liquid frame 38 and the outer surface of the elongated tubular portion 48 of the combination 18 . A resilient O-ring seal 50 is attached to the hollow cylinder 46 to prevent leakage of cleaning fluid into this handpiece.
and the tubular portion 48. A removable sleeve 52 is attached to the distal end of the fluid structure 38 and wraps around the surgical tip 20.

Suction passageway 56 communicates from its free end through the central axis of surgical probe 20 with the axial passageway of elongate tubular portion 48 of coupling body 18 . This passage 58
has a suction port communicating with the suction chamber 60 of the liquid frame 38 located between the O-ring 50 and the gasket 36. This outlet conduit 62 is connected to a vacuum chamber for aspirating irrigation fluid and emulsified tissue from the surgical site.

The structure and operation of the ultrasonic surgical handpiece according to the present invention is substantially similar to prior art devices, except for the shape of the vibration-inducing body. Then,
Only the vibrating body components of the ultrasonic surgical handpiece of the present invention will be illustrated and described.

In FIG. 2 showing a preferred embodiment of the present invention,
The vibrating body 68 is a transmission element or coupling body 7 suitable for assembly to support elements and framework parts in the manner described above.
2. The magnetostrictive transducer 70 is tightly assembled and supported by the magnetostrictive transducer 70. The magnetostrictive transducer 70 and the combined body 72 form a transducer with a length of 3/4λ. In addition, the surgical tip 74 having a length of 1/4λ is connected to the combined body 7 on the nodal surface or near the nodal surface.
It is assembled at the other end of the coupling body so that a sufficient wavelength can be obtained at the coupling part with 2. Both the prior art linear transducer shown in FIG. 1 and the bending transducer of the present invention shown in FIGS. , designed to resonate at a predetermined resonant frequency.

Both the transducer with the linear coupling and the transducer with the bent coupling make this particular surgical tip resonate along the longitudinal axis of the surgical tip at the same frequency. must have a vibrational impedance suitable for resonating the surgical tip at the desired or calculated frequency for the surgical tip. In fact, for a surgical chip designed to resonate at frequency F, there are upper and lower calculated frequency band limits within which the transducer will operate well. This frequency band is expressed as 2ΔF or the frequency F as F ₀ ±ΔF. The ultrasound generator or drive unit is thus designed to drive the transducer at frequencies in the band F ₀ ±ΔF.

If the flexural transducer combination is formed by essentially bending the linear combination, and the surgical tip is assumed to resonate at the same frequency F as the linear transducer, then the flexural combination This installed chip will operate at a different frequency F'.
Further, this frequency change can similarly occur when the linear combination is shortened.

In FIG. 6, the longitudinal center axis X of the linear transducer and the longitudinal axis X' of the bend 76 of the transducer according to the invention are:
They intersect with each other at point C and are arranged to form an angle α. In particular, one end of the transducer 16 is coupled to the coupling end of the linear coupling at the second antinode plane, and the other end or end of the transducer is located at the first antinode plane. The first nodal plane is located midway between the first and second nodal planes, generally in the middle of the magnetostrictive transducer. The second nodal surface is located near the free end of the bond.

As shown in FIG. 6, the longitudinal central axes of the linear combination body 18 and the bent combination body 72 are located on the second antinodal plane indicated by point A. According to the invention:
The combined body of the bent handpiece has a vertical axis extending at an angle α with the vertical axis X of the straight handpiece.
It is made to resonate along X' and to resonate with both linear and flexural transducers designed to use the same surgical tip. what if,
If the longitudinal central axes of the linear and flexural combinations have the same length, the linear transducer will resonate at frequency F, and the flexural transducer will resonate at frequency F'. This frequency F' corresponds to the frequency of a short linear combination.

In FIG. 6, AB represents the total length of the linear combination, and AD represents the distance from point A on the antinodal surface to the nodal surface near the free end of the bent combination. Point C
represents the point where the vertical axes X and X' intersect, and the point E
represents the free end of the flexural joint along the longitudinal axis X'. As you can read from this diagram, AD=AC+
CE×cosα=AC+CD. In this way, the length AD of the bent type combination as projected onto the X-axis line is shorter than the length AB of the straight type combination, so the frequency F' of this bent type combination is higher than the frequency of the straight type combination. The vibroacoustic elements of known ultrasonic surgical handpieces are typically supported on or near the nodal surface to minimize loss of performance. If a machine is designed to vibrate an acoustic element at a resonant frequency F, if this frequency changes even slightly, the position of the wave node will also change, resulting in increased capacity loss and reduced efficiency. succeeded to. However, as mentioned above, this type of system is generally designed to operate in a narrow frequency band centered around the most frequent frequency F ₀ and extending above and below it. That is, the allowable operating frequency F=the most frequent frequency F ₀ ±ΔF. Within this narrow frequency band,
Although the efficiency remains virtually constant for practical purposes, outside this narrow frequency band the stability of the ultrasound generator is unpredictable.

In order to match the frequencies of the respective combinations of both straight and flexural handpieces for compatibility with conventional systems and surgical tips, the flexural transducer has the length shown in FIG. It has been found that the frequency F of the surgical chip can be matched without changing the ACE. This means that the bond 7 near the nodal surface
2 by a predetermined mass reduction by partial ablation at a portion of the bend 76 of 2, corresponding to diametrically opposed surfaces of the combination which are preferably of substantially circular cross-section over the entire length of the combination. This is accomplished by planing planar portions 78 and 80, respectively.
This plane part preferably lies in a plane parallel to the plane containing the longitudinal axes of the bent and straight parts of the combination. The mass and shape reduced by this planing are calculated by solving the following equation.

(ρSdx) ∂ ² ξ／∂ ² t ² = (SY∂ ² ξ／∂x ² ) dx Here, ρ = volume density S = area of shaded area (ρSdx) = mass of differential quantity dx ξ = displacement Y = Young It is extremely difficult to solve the above equation exactly; in fact, solving this equation involves a number of approximations that must be taken to provide appropriate boundary conditions for the mass loaded on the vibrating body. Requires a value. The solution to this equation is derived by the following formula to approximate the mass reduced by ablation.

M [2πD ² /4ρ] [CB - CBcosα] Where, D = Diameter of the bonded body on the nodal surface ρ = Volume density of the bonded body material CB = Length of the bending part When using this method, the linear coupling A bent type combination having the same length as the body, with a bend or flexure of the combination placed at the midpoint of the nodal surface and the antinodal surface, has the same frequency on its axis X' as the straight type combination. designed to resonate along the As previously mentioned,
Acoustic transducers are usually designed orthogonal to the nodal supports to permit the transmission of linear axial vector forces to the chip vibrating along the transducer. Therefore, whatever acoustic transducer bends are used, the transducer bends are usually located at the rear of the nodal supports or wave contact supports, as disclosed in the aforementioned U.S. Pat. No. 3,546,498. It was arranged.

Due to the curved portion of the acoustic vibrator at the rear of this nodal surface support Y-Y, the vibration of the acoustic vibrator is excessive due to the movement to the operating frequency of the acoustic vibrator and inducing resonance of the vibrator. There will be a loss.

This loss is primarily due to non-axial loads caused by the bends in the combination. This non-axial load generates a vector force that has not only an axial component but also a radial component. This radial component is an unnecessary component. The above losses can be minimized by the following method.

1. By keeping the operating stroke level of the surgical tip low to a selected level that is well suited to the desired surgical procedure.

2. By controlling unnecessary lateral stacking movements so as not to impede sufficient cooling water flow.

3. By fully adjusting the vibrational impedance due to the mass of the combination to suit not only the mechanical suitability but also the surgical mode of use.

Thus, there has been a long-awaited need for an instrument that would enable the use of ultrasonic surgical handpieces in delicate surgeries that make microsurgery difficult. Additionally, the instrument is compatible with conventional drive and surgical procedures such that operating room personnel can easily interchange this flexure handpiece with a conventional straight handpiece without much practice or retraining. Allows the use of chips.

In the preferred embodiment of the invention shown in FIGS. 7A and 7B, the magnetostrictive transducer 70 is secured by support means arranged in the nodal plane Z-Z to tightly clamp it. is supported by This support means comprises a plurality of radially inwardly directed projections 8 on the inner wall 86 of the support element 32.
4. In addition, this support means
It has means intended to ensure sufficient cooling fluid flow around the transducer 70. The means for allowing this coolant to flow is formed by gaps 88 provided between the plurality of protrusions 84.

According to the invention, the combination comprises a substantially straight first portion having a longitudinal axis coincident with the longitudinal axis X of the transducer;
and a substantially linear second portion having a longitudinal axis X' extending in the direction of an angle α with respect to the longitudinal axis The part is formed to have a circular cross section, and a part of the surface of the bonded body is cut off near the nodal surface, so that the mass of that part of the bonded body is equal to the length of the bonded body in the same cross section and along the longitudinal axis X and the longitudinal axis X'. Calculate the mass that would be reduced by partial ablation even for a bent transducer with the same length as a linear transducer. By doing so, it became possible to make the resonant frequency the same as the linear type. Therefore, it is possible to use surgical handpieces having straight and curved transducers of the same length interchangeably.

Although the preferred embodiments of the present invention have been disclosed and described in detail, the present invention is not limited thereto, but rather includes all embodiments and the present invention, which are evident to those skilled in the art. It is considered that all embodiments that are clearly derived from the idea and viewpoint of the invention are included.